Method of forming plates for runways in spiral chutes and the like



March 9, 1948. I KAUTZ 2,437,259

METHOD OF FORMING PLATES FOR RUNWAYS IN SPIRAL CHUTES AND THE LIKE Filed March 20, 1943 2 Sheets-Sheet l March .9,- 1948. I I F, u-rz v I v 2,437,259 METHOD OF FORMING nuns FOR RUNWAYS m SPIRAL CHUTES m) THELIKE I Filed March 20 1943 2 Sheets-Sheet 2 T n-flit] arm-am lkfbmvck Aug/r2,

Patented Mar. 9,

Y UNITED sTATES PATENT. ,o F'FICE" a e 19 Claims. 1 V

This invention relates to, spiral chutes having a helical winding runway and also to .curved chutes which are 'fractions'of spiral chutes,although in such curved chutes the runway. may not always be of true helical shape. In particular, the invention deals withmethods of forming sections from whichlthe runways of said chutesare'to be assembled. I

In building metallic spiral'and curved chutes; the shaping and assembly of the runway has been often diflicult andexpensive. Use of large portions of sheet metal is not to be recommended as too diflicult to shape and,instead, smaller sectional portions or flights are employed. Such flightsrequire to be pre-shaped unless consisting of narrow strip-like sheets which may be readily placed in respective positions accompanied, however, by the disadvantage of retarding the assembling operationon account of more numerous flights due to the narrow width thereof. The degrees of shaping are largely dependentupon the degree of helical progression or"drop" of the runway. Generally, the degree .of the shaping operation of the flights increases with the steepness of the runwayand with the reduction of the diameter of its inner helix. in combination or respectively.

One of the best methodsheretofore employed is the shaping of'the flights by dies underpressure, but this method has the disadvantageof being inflexible, as it would require greatex pense to provide die facilitiesfor every possible helical progression and Width of runways in commercial demand. In practice, this method is limitem-therefore, to certain, most often used chutes.

Shaping by manual hammering 'or application of drop hammers has also been used, but such methods are slow and requireskilled operators.

It is, however,possible'to'eliminate the need of shaping said flights by reducing them-to narrow strips of sheet metal; but in such arrangementthe more numerous flights would'retar'd assembling considerably. 1 s

In considering the characteristics of a helical or similar contour of a 'runway,ione notes'that the difference of the progression "between the outer and inner peripheral edges requires the opposite ends of aflight to be disposed in different planes and a flight therefore, must undergoa. gradual twist to meet such requirement. 3

v In shaping such flights accordingly, it has been .found that certain portions of;the sheet metal expa'ndand other portions contract. It also has ,been evident that the sheet metal submits more readily to expansion. but resists contraction, and the difiiculties encountered in the shaping processi'are caused by the-latter fact.

. Itis therefore-one'of the main objects of this invention. to. provide a respective forming processhrmthod employingflights or sections-subjectedltotheiorming of'a shape in which said resistancejto contraction. of the material is considerably reduced in order to facilitate and simplif,y.said.process by minimizing the effect of thflmain obstacle. encountered in forming. It is another aim ofv the ,invention to provide flight units consisting initially of separate or partly separated portions with shapes equally favorableto said reduction .of theresistanec to'contraction and intended to be subjected to forming methods collectively, so that said' units can be madeof sizes ,torep'resent larger sections or sectors in runways than usuallyzfound practical inconven'tional forming methods. It is an additional object of theinvention to provide an inexpensive sh aping process for said flights by manual methods or pressure devices or by combined f rt -U...

A further object of the invention'is to provide a shaping process of flexible nature so. as to be applied to all varyingconditions in said chutes, without involving extra costs.

Still anotherobject shall provide for the, utilization of welding in said shaping process to obtain better results.

Additionalobjects, advantages and features of invention willbe apparent and better understood from the following detailed description and the drawings; wherein, v

Figure 1 isa perspective view of a spiral chute embodying the novel flight arrangement,

Figure 2 is a detail view; of two reciprocal flights; before shaping. I

' Figures 3t'o 6" are detailed views of flights in several modifications; before shaping. ,7

Figures rand 8 are perspectiveviews of flights showing the shaping process byvpressure devices inprinciple' v Figure 9 is a perspective view 7 of a shaping apparatus for-the novel flights.

Figures to 14 are detailed views of further modifications of the flights, before shaping.

Figures 15 and 16 are fractional top plan views of modifications of flight arrangements in a spiral chute.

The invention utilizes in the runways of referred chutes sectional plate or flight portions of prematurely reduced shape towards the center of chutes with the resulting unfilled space compensated by reciprocally disposed similar portions with outwardly directed reductions. These portions are preferably cut to a substantially triangular shape and combined in units in which ordinarily alarger and smaller portion, reciprocally directed to each other, have their wider ends located at the outer and inner peripheries.. of the assembled runways respectively with ad-" jacent edges of the portions forming substantially diagonal lines in the units. combined are subjected to a forming operationcollectively in order to acquire the helical contour The portions thus.

4 flights it which essentially represents the novel feature of the invention.

Due to the characteristic nature of a spiral chute, the outwardly pointing flights are smaller in comparison to the larger inwardly pointing flights, and the sides of the triangles located at the edges of the runways are curvilinear. As shown, for example, in Figure 1, each of the complementary flights reach fully across the runway and their contacting edges alternately lie in a radial line and at an angle thereto, although other arrangements may be used in which each of said edges are located angularly to the radial lines as explained hereinafter.

The small area in which spiral chutes can be placed is recognized as one of their main advantages. Of these chutes, the closed center type is more preferred for reasons of its compactness and narrow transverse dimensions resulting vfromhthe small diameter of the inner a helix of the-runway made possible by the use of sections in runways, as desired, and thereuponi i united, preferably by welding, at said diagonal edges. In one of the modifications of the invention, integral plates with partial division along diagonal lines are employed to obtain referred triangular and reciprocally directed portions which, in turn, are likewise formed and united, preferably by-welding, at the edges of said diagonal divisions.

Due to thetriangular shape of the portions in said units,-the resistance to contraction of the material and, therefore, to twisting motions is considerably reduced, as the b'roa'der ends of the portions remain substantially in the planes of the outer and inner helix of the chutes respectively and only the more narrow, tapered sections of the portions must be warped, and which can be carried out e'fficiently by simple manual or mechanical means, especially, as has been found, if said portions are treated collectively, as indicated.

As shown in the drawings, It! represents a spiral chute having a central tubular structure II, in vertical position, also known in the art as the center post, to which a helic'ally winding runway I2 is secured. The outer edge of the runway is lined by a sheet band 13 at right angles thereto serving as outer guard rail to prevent the conveyed objects from being dislocated, and for the inner guard railfthe center post takes the place. For the purpose'of illustrating my invention, only one type of spiral chute is shown, known as theclose'd center chute,"but there are other chutes in use in which the center post is replaced by an inner guar'cl' ra'il similar to the outer one here shown, and the outer guard rail may also be replaced or supplemented by a cylindrical casing or housingenveloping the entire chute.

In the present instance, the spiral chute is shown as a welded structure, since it is superior to other methods of fastenings, such as riveting or bolting, which, however, may also be used is found desirable.

The runwayis-composedofa plurality of sectional portions or flights 14 having their con.- tacting edges in overlapping relation and secured together by intermittent welding, preferably at the undersides of the chute, as indicated at I5. These flights are of substantially triangular shape and arranged in such way as to have inwardly pointing flights I'B supplemented by reciprocally located outwardly pointing of a tubular core member. In comparison thereto, the open center type spiral chutes include usually wider transverse dimensions caused by the larger diameter of said inner helix and respective inner support structure instead of a tubular core which is'impractical in this instance, due to said larger diameter of said helix. Described difiiculties in respect to shaping and forming of the flights have been, however, more apparent in the. preferred closed center type spiral chutes in view of the proximity of the inner helix therein to the central axis as previously indicated. The respective forming processes of the invention deal, therefore, preferably with the latter type of chutes. In accordance with the customary practice, the center post 1! or core in chute l0, determining said inner helix, is shown with a diameter corresponding to a fraction of the width of runway l2. Said diameter usually varies in practice from approximately one-half to one-fifth of the runway. The proportions of the flights may not be considered to have the shape of narrow strips. In particular, the dimensions of the ends. of the inwardly pointing larger flights l6 at outer periphery of runway l2 are.

shown to be at least one-third to one-half the width of said runway, a proportion which requires a distinct shaping operation for conventional flights of respective equal dimensions combined with a helic progression of the runway amounting at one revolution at least to the dimension of the double. width of said runway, as further indicated in the structure of Figure 1. All described proportions in combination contribute largely to the difllculties of shaping the flights ordinarily encountered.

The. described shape of the flights of the invention in combination with the reciprocal ar rangement facilitates the shaping process considerably. It becomes obvious that the broader portions of the flights can be :easily secured to the respective .plane of the outer and inner helix of the runway .and left unchanged in this location, and only. the smaller tapered portions must be twisted which is easily performed as the resistance of the. material in the latter portions to such process is butv slight.

For obtaining betterresults and especially to facilitate the use of flights comprising larger sections in the runway as heretofore employed, the following shaping method is recommended.

Av large and small substantially triangular flight, as in Figure 2, is abutted in reciprocal relation to each. other and :united bytack welding at welding, as inFigure or, an integral flight of the same shape may be provided having said diagonal division I! stopping short near both opposite ends as in Figure 6. V In such flights (Figures 3-6) atwisting is easily performed to disposethe respective portions in the plane of the outer and inner helix of the runway, as in Figure 7. The dividing line of two different planes is provided by said diagonal cut which alsoeliminates the resistance of the material to the twisting method.

In securing the opposite endspr such flights to saidlocations which may be alsodone by welding them directly to the chute, a subsequent application of blows orpressure along said diagonal line, principally from a vertical angle to the flight, as indicated by the arrow I8, in Figure 8, will depress the diagonal ridge, as shown in Figure 7, and bring about a gradual equilibrium in the material between the two different planes of said opposite ends.

By such method, the mutually abutted edge portionsalong said partial diagonal division move in reciprocal direction to an overlapping relation which is most apparent at the middle sec tion of said tetragonal units, resulting in a shrinkage of the material which can freely take place, due to said diagonal division. Said overlapping joint is subsequently secured together, preferably by tack welding atthe under side, thus completing the shaping process, except for small irregularities in the material which may be easily adjusted by light hammering. The heat radiated from welding further increases "the desired shrinkage effect with beneficial results on the formed shapeof the units. 7

' Likewise, in a unit as in Figure 4:, in which the edges are already overlapped, said shaping process further overlaps the material at said middle portion. The separate unshaped portions of Figure 2..may be treated by the same shapin process if means'areavailable to secure the opposite ends firmly to respective grades of chute. For i'nstance, one of .such means is provided-by welding said ends directly to the chutefollowed by pressure or'blows to obtain desired results as described.

This shaping process takes in account the fact that in twisting a sheet of tetragonal shape, the contraction of thernaterialis substantially centered alonga diagonal line and the expansion along the outer edge portions, and as described, the resulting difllculties causedby these circumstances are effectively eliminated, either by diagonal division or the similar use of triangles in reciprocal relation.

..The formingjig IQ of Figure 9 may serve as a further aid to ease and speed up the shaping process.. Mounted on a base 20, two spaced anvil portions 2| and 22 are located at an incline corresponding to the desired respective outer and inner pitch of-the chute. These portions may be channel members as shown, the hollow sides facingeach other so as to be able to receive within the ends of the flight'unitsiliigures 3 to 6) which preferably are twisted beforehand, assho'wnin Figure '7. Respective fasteners, in the present instance, bolts 23 with operating handles threaded through the walls of 'the channel members are used to secure the ends of the flight firmly to the inclined position of'the anvil portions-whereupon a pressure device 24v is operatedto depress the ridge portion in the flight: unitalong said diagonal division. In the present; instance, a worm- 25 with an -operating handle-is chosenas such pressure device,'held in position bya bra'cket anchored to the 'baseof the apparatus; To prevent denting of-the entire flight unit, theedge portions are supported by bar members which connect the spaced inclined anvil portions, leaving such an ample space-open at the under side of flight as to have an unobstructed access for application of welding at the diagonal seam after shaping. Said connecting bar may follow a straight or curved course dependent on' the desired nature of the runway (straight or concave). Alsothe incline of theanvil portions as well as the width of the jig may be made'adjustable, so as to comply with all possibilities of flights or runways. The pressure may also. be supplemented by a leverage device!!! heeled and pivoted to the radial edge of the flights and reach' therefrom towards the mutual seam of the 'flight portions, so as to depress the area of the seams; Obviously, other means may be employed. Flight units after being shaped in a jig as described and shown,

may be incorporated in chutes by welding, bolt was 2, 5 and 6 respectively; In these forms, saiddiagonal division is provided by a slit obtained bythe respective curvilinear edge portions. The

slit being of a width corresponding to the contraction of the material, is subsequently closed in the shaping process, whereupon the resulting'but seam is secured together by welding. In this manner, smooth flight units are obtained.

In'Figure 13, the diagonal division is deviated from regular course by an angular bend 26 which may also be substituted by a curve. In such manner, it is possible to better regulate the deepest level of concavity in a runway at a location as desiredr In another modification of the invention, a flight unit is provided in which the inwardly directed larger section may be subdivided into two smaller portions by an additional division as shown in Figure14. Therein, the tetragonal flight is represented as having a cut I! following a diagonal line and the larger of the two sections thus obtained is halved by an additionalout. These cuts are performed; as shown in Figure 5, stopping near one end of the flight, the opposite end of the cuts being closed by tack welding which is, however, not the exclusive way of obtaining such cuts as shown before and it is un derstood that other methods may be followed.

Various methods of forming such flight units may be employed such as manual twistingof the portions or pressure devices applied. In the latter case, the outer ends of the inwardly directed portions are held in an identical plane contrary to the end of the outwardly directed portion in accordancewith the diflerential outer and inner grade of the chute. The pressure or blows are principally applied along said diagonal division as previously described to obtain said resulting contraction in the material and the process is to be supplemented by pressure upon said division halving the'larger flight portion for further contraction and :adjustment of the material of said area. The thus treated portions are secured together as previously described.

Such method may be especially appropriate in shaping extra large flights to be used for obtaining quicker assembling results.

The flight unit as shown in Figure '14 may be also composed of three separate triangular portions having two portions successively pointed inwardly relative to chute and supplemented by a portion disposed in opposite direction, to be'followed by subsequent connecting of the mutual seams by tack welding at outer ends to obtain said divisions preparatory to shaping, or, said separate flights may be directly welded to outer and inner helix of chute in'stated succession and formed thereafter by pressure devices or other methods as outlined before.

The curvilinear edge portions shown in Figures 10, 11, 12, etc., may be used in the above arrangement for the same purpose and eflect.

In Figure 15, the contacting edges of flights follow alternately a radial line 28 and a line at an angle thereto, as in Figure 1. Such disposition of seams caused by a respective shape of the triangular flights orflight portions is best suited for runways having a, straight transverse runway. For concave runways the arrangement of Figure 16 is preferable, in which every contacting seam of the flights lie in a line at an angle to the radial line.

By giving the triangular flightsa scalene shape, the angularity of the seamsrelative to a radial line may be still increased to obtain an even greater concavity of the runway if desired.

It is understood that the disclosures herein serve for the purpose of illustration only, and that the flights may be subjected to changes regarding size, proportions, shape, and that they may be used on helical or otherwise curved chutes of various kinds.

I claim:

1. The process of forming a sectional unit in the runway of a chute conveyor of the tortuous kind or the like, consisting in preparing plates of tapered shape, arranging said plates in units and forming said units so as to acquire the contour of said runway with the aid of an apparatus having a base in which two opposite planes corresponding to the oute and inner grades of the assembled chute conveyor respectively and said apparatus further having retaining means at spaced portions and a pressure device operable upon said base, and said respective steps of arranging and forming said units, comprising placing said tapered plates upon said base in recipro cal relation to each other with respective edge portions thereof in mutual adjacency, and attaching respective peripheral ends of said plates lying at the outer and inner curve in the assembled chute conveyor to said spaced portions with said retaining means thereby disposing said plates in the plane of said outer and inner grade respectively, depressing the material of said plates lying inwardly from said spaced portions by operating said pressure device thereupon so as to cause a movement of said edge portions in the direction of the pressure combined simultaneously with a reciprocal and gradual turn of the planes of the plates between said peripheral ends and eifect a gradual equilibrium in the material between said respective grades, and completing said unit icy-securing adjacent-edge portions of said plates to each other.

'2. The process of forming 'asectional unit in the runway of a chute conveyor of the tortuous kind or the like, consisting in preparing a unit of plating with a substantially diagonal division stopping short near the edges, forming the thus partially divided sections of said unit so as to acquire the contour of said runway with the aid of anapparatus having a'base in which two opposite planes corresponding to the outer and inner grades of the assembled chute conveyor respectively and said apparatus further having retaining means at said spaced portions and a pressure device operable upon said base, and the step of forming said unit comprising placing said unit upon said base and attaching respective peripheral ends thereof lying at the outer and inner curve in said chute conveyor to said spaced portions with said retaining means thereby disposing-said sections in the plane of said outer and inner grade respectively, depressing the material of said unit lying inwardly from said spaced portions by operating said pressure device thereupon so as to cause a movement of the edge portions of said sections at the diagonal division in the direction of the pressure combined simultaneously with a reciprocal and gradual turn of the planes of the sections between said peripheral ends and effect a gradual equilibrium in the material between said respective grades, and completing the union of said sections by securing respective edge portions at said diagonal division to each other.

'3. The process of claim 1 in which the step of securing said edge portions to each other is performed by welding applied at the side opposite from said pressure device, made accessible by a substantial opening in the base of said apparatus.

4. The process of claim 2 in which the step of securing said edge portions to each other is performed'by welding applied at the side opposite from said pressure device, made accessible by a substantial opening in the base of the apparatus.

5. The process of forming sections in the runway off-a chute conveyor of the tortuous kind or the like in which the width of the assembled runway is ofa dimension greater than the diameter of the inner tortuosity of said runway, the steps which comprise providing units of flat material having at least two reciprocally directed portions with tapered reductions in area supplementary arranged so as to converge substantially in inward and outward direction respectively relative to the assembled chute conveyor to dispose the wider ends of said tapered'portions at the outer and inner periphery of the assembled runway respectively, with respective edge portions of said tapered portions in mutual adjacency and with said wider ends of said inwardly directed portions insaid units of a length corresponding at least to one-third of the width of said runway and further,- with said tapered reductions of the inwardly directed portions substantially increased in comparison to such sectors in the plane of the assembled runway with wider ends at said outer periphery equal in length to such in said in wardlydirected portions, forming said units so as to acquire the contour of respective sections in the assembled runway by forcing the material of said units to undergo twisting motions with pivotal axes lying at lines substantially transversely to assembled runway permitting simultaneously an areal readjustment of said units by respectivev motions of. said portions and said adjacent edge portions respectively in relation to each; other inorder to; dispose said wider ends of said portions in the respective different grades or 'theouter and inner, peripheries of theassernbled runwayand the material or said portions therebetween "in co-ordinated and graduated planes so as to efEectag'raduaI equilibrium between said respective grades and by said read- Justment reflecting a change in thearea of said units as means" for facilitating said step of forming, anduniting said tapered portions in said units by securing said adjacent edge portions to eachother. 7

:6. The process of forming sectionsin the runway of a chute conveyorfof the tortuous kind or the li l e,- the steps which comprise providing units ofriiat material having at least two reciprocally directed portions withsubstantial tapered reduction in area supplementary arranged so as to converge substantially in inward ando'utward direction respectively reiative to the assembled chute conveyor to di'spose-respective edge por m re o S i e rtions" in r' bs ni iy diagonal line in'said unit'sand in mutual adjacency e tive to e c t e w h th er, end f said tapered portions forming substantially the ends of said units lying ,at theouter and inner peripheryoi the assembledrunway respectively, iorniingsaid units so as to acquire the contour of respective sections in the assembled runway by'j'placing said tapered portions in the difierent grades ofthe outer and inner periphery of the assembled" runwayrespectiyely and employing means for retaining said wider e'ndsef said tapered portions in said respective positions and further forcingthe material 'of said tapered portion sztherebetween tonundergo twisting motions with" "pivotal axes atline's' lying substantially transversely to the assembled runwaycombined with athereby'initiated reciprocal readjustment of said tapered portions and said adjacent edges respectively in relation to each other substantially between said retained ends in order to dispose the material of 's'aidtj'apered portions therebetween in co-ordinated and graduated planes, so as ,toeffect a' gradual equilibrium between said respective grades and byisaid readjustment effecting ajgradual 'shrinkagein thejarea of said units between said retainedends as means for facilitating said step of forming, and uniting said tapered portions in said units by securing said adjacent edge portions toJeach' other.

' "LThe process of claimj in which the step o .p' parineis id. ur ts ine l e disposing Said. adjacent-Ledgeportions in substantially abutted relation relative to each other vto be changed to gradually overlapping relati n bet e s wper ripherail ends by said; areal readjustment in the steppf forrning said units asmeans for obtainingsaid change in v the area of" said units.

, 3.: T e P s o cla m v i wh hihef i ep of preparing said un'itsj includes cutting said tapered portions to a substantially triangular V shapes j 7 j 9. The process -of claimfi-B injwhich the step e of preparingsaid-unitsincludes the provision of a major portion converging inwardly relative to the, assembled chute conveyor supplemented by a' reduced portion reciprocally' directed thereto.

'10.]"Ifhe' process of forming a, sectional portion in the runway eta-chute conveyor of the tortuous kind or thelike, the steps which com- P ise: 'pr'fii 'aring platefhavingapartial substantially diagonal extended division so as to.

torin partially-divided tapered-sections con' nected 'to each" other outwardly from the 'ter' nifnals of said division and with respective edges of said sections converging substantially in 111- 10 ward and outward direction respectively relative to the assembled chute conveyor with wider ends of said tapered sections lying at the outer and inner periphery of the assembled runway respectively, and with respective edge portions of said sections at said division in mutual adjacency, forming said plate so as to. acquire the contour of a sectional portion in the assembled runway by forcing the material thereof to undergo twisting motions with pivotal axes at lines lying substantiallytransversely to the assembled runway and in a manner permitting simultaneously an areal readjustment of'said plate by respective motionsof said sections and said adjacent edge portionsrespectively relative to each other in order to dispose said wider ends of said sections in thedifierent grades of the outer and inner peripheryof the assembled runway respectively andthe material of said sections therebetween in coordinated and graduated plane'ssoas'to effect a gradual equilibrium between said respective grades" and by said readjustment efl'ectinga disposition of said adjacent edge portions in overlapping relation to each' other gradually inwardly from opposite terminals of said division resulting in a respective shrinkage in the area of saidplate as means for facilitating said step of forming, and uniting said (sections of the plate by securing said overlapped edge portions to each other. V i

11'. The process of claim 10 in when the step of preparing said plate includes providingsaid plate for a chute conveyor infwhich the width of the assembled runwayis of a dimension greater than the diamete'r of theinner tortuosity of said runway withwider end=of a respective inwardly directed section at the outer periphery of the assembled 'runwayof a length corresponding at least to one-third of the width of said runway.

12. The process of claim 10 in which the step of forming said plate includes attaching the wider ends of 'said sections lying at'the outer and inner periphery of the assembled-runway respectively to supportsin the-respective planes of the outer and innergrade of said runway so as to have-said sections disposed in said planes respectively with saiddiagonal division as a dividing line, applying pressure upon said plate as means for obtaining twisting motions with pivotal axes lying substantially'at the outer edges of said plate extended between said outer and inner periphery in order to force the material of said sections in said coordinated and graduated planes between said attached and substantially'constant ends and saidadjacentedge portions insaid overlapping relation for the purpose of obtaining said shrinkage; I

13: The process oi forming a section in the runwayof. a chute conveyorof the tortuous k nd or the like, the steps which comprise the cutting of plates to substantiallytriangular shape. attaching ends of two plates lying at the outer and inner periphery of the assembled runway respectively to supports in the respectiveplanes of ,t-e outer and inner-grade of said runway so as to have said plates disposed in saidplanes respectively in supplemental and reciprocal relation to each other with converging edges of said plates extended friom, said attached endssubstantially in inward and outward direction respectively relative to the assembled chute conveyor and with respective edge portions of said plates in mutual adjacency to form "a dividing line between said planes, forming said plates so arranged as'a unit so as to acquire the contour of a respective sectionof the assembled runway by applying pressure thereupon and in amanner: so as toforce the material thereof between. said attached and substantially constant-ends to undergo twisting motions with. pivotal axes lying substantially-at the outer edges of said plates extended between said attached ends combined with a'thereby initiated areal readjustment of said unit by respective reciprocal motions of said plates and said adjacent edge portions substantially inwardly from said attached ends in order to=dispose the material of said plates between said attached ends. in coordinated and graduated planes so as to effectagradual equilibrium between said outer and inner grade and by said readjustment effecting a shrinkage in the area :o-fsaid unit between said attached ends centered principally at midsection of said unit as means for facilitating said step of forming, and uniting said plates by securing said adjacent edge portions to each otherr 14. The process of claim 13 in-which the step of forming said unit provides applying pressure at an area concentrated along said adjacent edge I portions of the plates.-

diagonally extended division performedby a partial cut in the material of the platealong a diagonal line stopping short near an edge portion. of said plate at one side and'closing,saidscutby welding near anedge portion. or said plate atanother side so as to form partially divided tapered sections connected to each other. between said edge portionsand terminals of said division and. convergingv substantially in inward and outward directionsv respectively relativeto the=assembled chute conveyor with wider endsrof said tapered sections lying at the outer and inner periphery of the assembled runway respectively and with respective edge portions ofsaidsections at said. diagonal line in mutual adjacency, forming said plate so as toacquire the contour of arespective sectional portionin the assembled runway by distorting the material of said sections about pivotal lines lying substantiallyin transverse directionsto the assembled runway in order to dispose said wider ends. of. the sections in the grades of the outer andinner periphery of said runway respectively and the material of said sections therebetween in coordinated and graduated planes so as to effect a gradual. equilibriunibetween said respectivegrades, and uniting, saidsections or the plate by securing said adjacent edge portions to eachother.

1'7. The process of forming a. sectionalrportionl in the runway of a. chute conveyor ofv the totuous kind or. the like, the. steps which comprise preparing. a unit of fiat material .withapartial sub-- stantially diagonally extended division performed by arranging separate sections. oftapered shape in reciprocal relation. to each other and welding the adjacent edge portionsthereof together near marginal edges. of said unit so as to form partially divided tapered sections separated from.

each other inwardly from said weldedconneotions and converging substantially in inward and.

outward direction respectively relative to the as.-

sembledchuteconveyor with wider ends of said tapered sections. lying, at the outer and inner periphery of the assembled runway respectively, and with respective edge. portions of said sections at said. diagonaldivision in mutual adjacency, forming said unit so as to acquire the contour of a respective sectional portion in the'assembled runway by distorting the material of said sections around pivotal lines lying substantially in transverse directions to the assembled runway in order to dispose said wider ends of the sections in the grades of the outer and innerperiphery of said runway respectively and the material of said sections therebetween in coordinated and graduated planes so as to effect a gradual equilibrium between. saidrespective grades, and uniting said sections by securing said adjacent edge portions to each other.

18. The process of forming a section in the runway of a chute conveyor ofthe tortuous kind or the like, the. stepswhich comprise providing a unit offlat material having reciprocally directed portions with. tapered reduction in. area supplementarily arranged so as to converge substantially ininward and outward direction respectively relative to. the assembled chute conveyor with wider ends of .said portions lying at the outer and inner periphery of.the assembled. runway respectively and with respective edge. portions of said tapered portions partiallyseparated from each other by a slit inwardly from said respective wider ends produced by cutting said edge portions on curvilinear. lines, formingsaid'unit so as to acquire the contour of a respective section in the assembled runway by distorting the material: of said.

portions around pivotal lines lying, substantially in transverse directions to the assembled runway in. a manner permitting simultaneously an areal readjustment. of said unit inorder to dispose said wider ends of the portions in the gradesof the outer and inner periphery of said runway'respectively and the material of said portions therebetween in. coordinated and graduated planes so as to effect agradual equilibrium between said respective grades and closure of said slit by reciprocal approach of said'portions in the course of said readjustment, and unitingsaid portions by weldingrespective edge portions thereof at the closed slit to each other..

19. The process of forming a section in the runway of. a chute conveyor of the tortuous kind or the like, the steps which comprise providing a unit of flat material having. reciprocally directed portions of varied size with substantial tapered reduction in area supplementarily arranged so as to have a major portion converging in inward direction relative to the assembled chute conveyor and. a reduced portion reciprocally converging thereto with wider ends of said portions lying. at. the outerand inner periphery of the assembled runway respectively and with respective edge portions of. said portions disposed in. mutual adjacency anddeviatedfrom a diagonal line in said. unitin order to. decreasefithe area of the major portion combined with a respective increase ofthereducedportion substantially inwardly from said Wider peripheral ends comparativetorespective portions divided by a diagonal line, forming said unit so as to acquire the contour ofv arespective section in the assembled runway by distorting the material of said portions about lines lying substantially in. transverse directions to the assembled runway in order to dispose-said wider ends of said portions in the gradesof the outer and inner periphery of said 13 14 runway respectively and the material of said por- TED tions therebetween in coordinated and graduated UNI STATES PATENTS planes so as to efiect a. gradual equilibrium be- Number N D tween said respective grades, and unting said. por- 1,526,917 a d b. 17, 1925 tions of the unit by securing said adjacent edge 5 1,360,521 Anderson y 1932 portions t each t 2,344,444 Malczewski Mar. 14, 1944 FREDERICK KAUTZ, 2,235,461 Miller Mar. 18, 1941 817,278 Schwab Apr, 10, 1906 REFERENCES CITED 1,515,890 Sekulski Nov. 18, 1924 0 1,965,736 Dillman July 10, 1934 The following references are of record in the 1 2,320,805 Smith M June 1, 1943 file of this patent: 

